package com.heimali.happyreader.utils;

import java.io.UnsupportedEncodingException;
import android.text.TextUtils;

public class StringUtils {
	public static String iconv(String inCharSet, String outCharSet, String content) {
		String res = "";
		if (TextUtils.isEmpty(content)) {
			return res;
		}
		
		try {
			res = new String(content.getBytes(inCharSet), outCharSet);
		}catch (UnsupportedEncodingException e) {
			res = "";
		}
		
		return res;
	}
	
	public static String ltrim(String source, String charlist) {
		String res = source.replaceFirst(charlist, "");
		if (res.length() != source.length()) {
			return ltrim(res, charlist);
		}
		return res;
	}
	
	public static String escape(String src) {
		int i;
		char j;
		StringBuffer tmp = new StringBuffer();
		tmp.ensureCapacity(src.length() * 6);

		for (i = 0; i < src.length(); i++) {

			j = src.charAt(i);

			if (Character.isDigit(j) || Character.isLowerCase(j) || Character.isUpperCase(j))
				tmp.append(j);
			else if (j < 256) {
				tmp.append("%");
				if (j < 16)
					tmp.append("0");
				tmp.append(Integer.toString(j, 16));
			} else {
				tmp.append("%u");
				tmp.append(Integer.toString(j, 16));
			}
		}
		return tmp.toString();
	}

	public static String unescape(String src) {
		StringBuffer tmp = new StringBuffer();
		tmp.ensureCapacity(src.length());
		int lastPos = 0, pos = 0;
		char ch;
		while (lastPos < src.length()) {
			pos = src.indexOf("%", lastPos);
			if (pos == lastPos) {
				if (src.charAt(pos + 1) == 'u') {
					ch = (char) Integer.parseInt(src.substring(pos + 2, pos + 6), 16);
					tmp.append(ch);
					lastPos = pos + 6;
				} else {
					ch = (char) Integer.parseInt(src.substring(pos + 1, pos + 3), 16);
					tmp.append(ch);
					lastPos = pos + 3;
				}
			} else {
				if (pos == -1) {
					tmp.append(src.substring(lastPos));
					lastPos = src.length();
				} else {
					tmp.append(src.substring(lastPos, pos));
					lastPos = pos;
				}
			}
		}
		return tmp.toString();
	}
}
